diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 8327e5e86d15..0a4cd24b6578 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -887,6 +887,7 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle) { struct tcp_sock *tp = tcp_sk(sk); struct sk_buff *skb; + unsigned int tso_segs, cwnd_quota; int sent_pkts; /* If we are closed, the bytes will have to remain here. @@ -896,19 +897,31 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle) if (unlikely(sk->sk_state == TCP_CLOSE)) return 0; + skb = sk->sk_send_head; + if (unlikely(!skb)) + return 0; + + tso_segs = tcp_init_tso_segs(sk, skb); + cwnd_quota = tcp_cwnd_test(tp, skb); sent_pkts = 0; - while ((skb = sk->sk_send_head) && - tcp_snd_test(sk, skb, mss_now, - tcp_skb_is_last(sk, skb) ? nonagle : - TCP_NAGLE_PUSH)) { - if (skb->len > mss_now) { - if (tcp_fragment(sk, skb, mss_now)) + + while (cwnd_quota >= tso_segs) { + if (unlikely(!tcp_nagle_test(tp, skb, mss_now, + (tcp_skb_is_last(sk, skb) ? + nonagle : TCP_NAGLE_PUSH)))) + break; + + if (unlikely(!tcp_snd_wnd_test(tp, skb, mss_now))) + break; + + if (unlikely(skb->len > mss_now)) { + if (unlikely(tcp_fragment(sk, skb, mss_now))) break; } TCP_SKB_CB(skb)->when = tcp_time_stamp; tcp_tso_set_push(skb); - if (tcp_transmit_skb(sk, skb_clone(skb, GFP_ATOMIC))) + if (unlikely(tcp_transmit_skb(sk, skb_clone(skb, GFP_ATOMIC)))) break; /* Advance the send_head. This one is sent out. @@ -917,10 +930,19 @@ static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle) update_send_head(sk, tp, skb); tcp_minshall_update(tp, mss_now, skb); - sent_pkts = 1; + sent_pkts++; + + /* Do not optimize this to use tso_segs. If we chopped up + * the packet above, tso_segs will no longer be valid. + */ + cwnd_quota -= tcp_skb_pcount(skb); + skb = sk->sk_send_head; + if (!skb) + break; + tso_segs = tcp_init_tso_segs(sk, skb); } - if (sent_pkts) { + if (likely(sent_pkts)) { tcp_cwnd_validate(sk, tp); return 0; }